Distinct magnetism in ultrathin epitaxial NiFe2O4 films on MgAl2O4 and SrTiO3single crystalline substrates

Spinel ferrites are being considered for advanced spintronic applications. Here, we report on the magnetic properties of ultrathin (3-37 nm) epitaxial films of NiFe2O4 (NFO) on MgAl2O4 (MAO) and SrTiO3 (STO) single crystalline substrates. It is found that NFO films on STO display superparamagnetic r...

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Detalles Bibliográficos
Autores: Foerster, Michael, Rebled, J. M. (José Manuel), Estradé Albiol, Sònia, Sánchez Barrera, Florencio, Peiró Martínez, Francisca, Fontcuberta i Griñó, Josep
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2011
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/32281
Acceso en línea:https://hdl.handle.net/2445/32281
Access Level:acceso abierto
Palabra clave:Espintrònica
Propietats magnètiques
Pel·lícules fines
Pedres precioses
Spintronics
Magnetic properties
Thin films
Precious stones
Descripción
Sumario:Spinel ferrites are being considered for advanced spintronic applications. Here, we report on the magnetic properties of ultrathin (3-37 nm) epitaxial films of NiFe2O4 (NFO) on MgAl2O4 (MAO) and SrTiO3 (STO) single crystalline substrates. It is found that NFO films on STO display superparamagnetic response down to 50 K, whereas films grown on MAO display ferrimagnetic response up to room temperature. Microstructural information indicates that this distinct response can be attributed to the different growth mechanisms of the spinel ferrite on the isostructural MAO substrate (two-dimensional growth) and the perovskite STO (Volmer-Weber three-dimensional growth). We discuss the reasons for this distinct behavior and its relevance for the integration of ferrites in epitaxial heterostructures for tunnel devices.